A functional film, in general, is laminated on the surface of an ophthalmic lens, for example, a lens for glasses, a contact lens, etc. The lamination method may be carried out by a method, for example, a transcription, a formation, etc.
As a method for forming a film on the surface of an ophthalmic lens, there is the Korean patent registration method No. 10-1283459 (registered on Jul. 2, 2013, a forming apparatus of a flat film on an optical lens, a functionalization method of an optical lens by this forming apparatus, and an optical lens).
As for the contents of the aforementioned registered patent, it is employing a method wherein a flexible flat film is directly attached to the surface of a lens, and the flexible flat film is deformed to match with the curvature of a lens by supplying pressure, whereupon it can be consequently attached to the front surface of the lens.
To this end, there are provided a mechanical piston which carries out a vertical translational motion, a module equipped with a plate engaged to the top of the mechanical piston, an anti-return device for limiting the height of the plate in the module, a lens holder for fixing an optical lens at the top of the plate, a film carrier for fixing the film at the top of the lens holder, a stamp which is laid vertical at the module, and a mechanical translational unit which allows the stamps to carry out a vertical and horizontal motion. In this configuration, a pressure can be supplied until the flat film can contact at equal angles with the lens with the aid of a relative motion between the stamp and the mechanical piston, by means of which the flat film can be attached to the surface of the lens which has a predetermined curvature.
In the aforementioned method, it is impossible to guarantee that all portions of a film can elongate at the same elongation percentages and can convert into a film having a predetermined curvature depending on a pressure condition and a film state during a procedure where a flexible flat film is converted into a flexible film having a predetermined curvature in such a way to directly press the flexible flat film on a lens having a predetermined curvature. For this reason, the reliability of a product may be degraded, and yield may be lowered.
In the aforementioned conventional apparatus, since a flexible plan film should be attached to every lens one by one, a mass production is not available.